Grease-sealed bearing with oxide layers

Abstract

The grease-sealed bearing is formed on rolling surfaces (4) of rings (2, 2) of the bearing (1) with oxide layers (5) having a thickness of 0.1-2.5 microns, the development of peculiar peeling on the rolling surfaces of the bearing can be prevented. If it is used as a bearing for an alternator or the like, its duration can be increased.

We claim: 
     
       1. A grease-sealed bearing having inner and outer rings that enclose a plurality of rolling elements, a cage for guiding the plurality of rolling elements, seal members for sealing said plurality of rolling elements enclosed between said inner and outer rings, and grease sealed therebetween, characterized in that oxide coatings having a thickness of 0.1-2.5 microns are formed on rolling surfaces of the rings. 
     
     
       2. A grease-sealed bearing comprising: a plurality of rolling elements;   inner and outer rings positioned with each other so as to enclose said plurality of rolling elements, said inner and outer rings each having outer and inner rolling surfaces, respectively, for operatively contacting said plurality of rolling elements, the rolling surfaces being formed with oxide coatings of 0.1-2.5 microns thickness;   a cage located between said inner and outer rings so as to guide said plurality of rolling elements;   seal members for sealing said plurality of rolling members enclosed between said inner and outer rings; and   grease filled between said inner and outer rings, said plurality of rolling elements and said seal members.